The Streptococci make up a medically important genera of microbes known to cause several types of disease in humans, including, for example, otitis media, conjunctivitis, pneumonia, bacteremia, meningitis, sinusitis, pleural empyema and endocarditis, and most particularly meningitis, such as for example infection of cerebrospinal fluid. Since its isolation more than 100 years ago, Streptococcus pneumoniae has been one of the more intensively studied microbes. For example, much of our early understanding that DNA is, in fact, the genetic material was predicated on the work of Griffith and of Avery, Macleod and McCarty using this microbe. Despite the vast amount of research with Streptococcus pneumoniae, many questions concerning the virulence of this microbe remain. It is particularly preferred to employ Streptococcal genes and gene products as targets for the development of antibiotics.
The frequency of Streptococcus pneumoniae infections has risen dramatically in the past few decades. This has been attributed to the emergence of multiply antibiotic resistant strains and an increasing population of people with weakened immune systems. It is no longer uncommon to isolate Streptococcus pneumoniae strains which are resistant to some or all of the standard antibiotics. This phenomenon has created a demand for both new anti-microbial agents, vaccines, and diagnostic tests for this organism.
Clearly, there exists a need for factors, such as the licC embodiments of the invention, that have a present benefit of being useful to screen compounds for antibiotic activity. Such factors are also useful to determine their role in pathogenesis of infection, dysfunction and disease. There is also a need for identification and characterization of such factors and their antagonists and agonists to find ways to prevent, ameliorate or correct such infection, dysfunction and disease.
Certain of the polypeptides of the invention possess amino acid sequence homology to a known licC protein. Polypeptide: NCBI non-redundant protein database: entry: gi.vertline.1074968.vertline.pir.parallel.D64128 lic-1 operon protein (licC) homolog--Haemophilus influenzae (strain Rd KW20) &gt;gi.vertline.1574381 (U32829) lic-1 operon protein (licC) [Haemophilus influenzae]; Polynucleotide: TIGR Streptococcus pneumonia sequences; available from The Institute for Genome Research via the internet (http://www.tigr.org/), Entry 4179; Weiser, J. N., et al., "Decoration of lipopolysaccharide with phosphorylcholine: a phase-variable characteristic of Haemophilus influenzae", Infect. Immun., (1997 Mar), 65(3): 943-50.